1. Field
Embodiments of the present invention relate to a flexible transparent conductive coating and a method of making the same.
2. Related Art
Conductive coatings are commonly found in modern electronic devices. Conductive coatings can be used to transmit electrical signals between components or can be used as a sensor, for example, to detect the presence of objects. When used in display devices, such as organic light emitting diode (OLED) displays, liquid crystal displays (LCDs), plasma display panels (PDPs), and the like, the conductive coatings may be transparent so as to not interfere with light emitted from the display panel.
Furthermore, touch panels may utilize conductive coatings to detect a touch by, for example, a stylus device or a human finger. Touch panels can be either resistive-type or conductive-type, for example. When the touch panel is used in conjunction with a display device, such as in a smart phone or a touch-screen display, various elements of the touch panel, such as the electrodes, should be transparent so an image displayed by the display device is visible to a user through the touch panel.
Recently, flexible display devices have become popular. Flexible display devices can be, for example, continuously flexible, that is, a user may freely flex the display device into a particular shape or orientation, or may be curved, that is, the display device may be manufactured flat but then bent to have a curvature (e.g., a preset curvature) in use.
There is a desire to use the touch panel in conjunction with the flexible display device, in which case the touch panel is desirably flexible as well as transparent while reducing or preventing degradation of displayed images due to the touch panel.
Conventionally, indium tin oxide (ITO) has been used as a transparent conductive material in, for example, touch panels and display devices. However, ITO includes rare earth materials (e.g., rare earth elements or rare earth metals) and, therefore, is relatively expensive. In addition, ITO is brittle and, thus, is not best suited for use in flexible devices.
Generally, reduction of sheet resistance (e.g., reduction in the resistance of a conductive sheet or coating) comes at the expense of reduced light transmittance. That is, generally, sheet resistance increases when greater light transmittance through the sheet is desired. Various approaches have been proposed to reduce sheet resistance without substantially reducing light transmittance therethrough, each having their own drawbacks. For example, metal meshes have been proposed. However, while metal meshes may have relatively high light transmittance and reduced sheet resistance, the metal mesh may be visible, causing, for example, a moiré pattern to be visible to a viewer.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention, and therefore, it may contain information that does not form prior art.